The invention relates to a brush and a method for producing a brush head particularly for dental use, and a machine for carrying out the method.
The brush head produced in accordance with the invention is particularly suitable for the so-called preventive dental care which includes cleaning of the teeth and massage of the gums to prevent caries and infection of the gums, including periodontics, etc. The brush head produced according to the invention can be used both on the dentist's drill and on home-care devices such as, for example, battery-driven dental care equipment with rotating drive mechanisms.
Known methods for producing brush heads include the step of carrying forward of a certain amount of fibers towards a hot tool so that the end of the fiber bundle is pressed hard against the heating head prior to the heating. The fibers are then melted together at their ends for the formation of the bottom which will then consist of the melted together fiber material which has been pressed toward the heating head. However, it is very difficult to ensure a constant amount of fiber material for the melting of the bottom, in that it is difficult in practice to obtain precisely the same abutment pressure on the tool every time. This is because the surface of the fibers is very smooth, and displacement will tend to occur between the feed mechanism and the fiber bundle. This gives different material amounts for the formation of the bottom, and if the fibers slide back in the feed mechanism retainer, the amount of material available will be insufficient in order to form the bottom and hold the fibers together in the bottom. This gives a risk of fibers working loose with consequent inconvenience for the user of the brush. Moreover, the bottom may become oblique in that the material is distributed unevenly at the bottom which provides bad contact with the retaining device to which the brush head is attached. It is the object of the invention to overcome these drawbacks by the known method, and this is achieved by an oblong fiber bundle which while held together is carried forward towards a heated melting tool for the formation of the bottom plate for the fibers, in that the fiber bundle during the melting is constantly carried forward toward the tool so that an extended bottom plate is formed, whereafter the fibers are cut off and the extended bottom plate is removed for the formation of the finished brush head.
This does to a great extent guarantee that the same amount of fibers is melted for the formation of the bottom in that the fibers are carried forward concurrently with the melting, and therefore no significant degree of pressure need be applied for pressing them against the tool. Hereby problems with insufficient fiber material are avoided, the only requirement being that the fibers are carried forward concurrently with their being melted at the ends. Moreover, a considerably stronger bottom is obtained in that there will always be abundant material for the actual bottom, whereas the remaining material is pressed out for the formation of a further ring member at the bottom which is later removed.
A further object of the invention is to provide a method of producing a brush head whereby it is both cheap and quick to produce the brush heads, and which in their production are provided with such a shape that they can effectively clean the teeth and massage the gums without in any way damaging the teeth or the gums. This object is achieved by producing the brush head as presented and characterized in claim. With just a few working operations and simple tools, one can produce a brush head so cheaply that it is possible to use the brush as a disposable brush which can be discarded after use, even though it is robust enough to be used repeatedly. The fact that it is disposable makes the brush particularly suitable for use in clinics, in that cleaning of the brush after use is avoided, whereas in the home-care of the teeth the same brush can be used innumerable times because it can be cleaned in the same way as a normal toothbrush, i.e. under running water.